Centrifugal separation container, centrifugal separation device, and centrifugal separation method using said container and device

ABSTRACT

A storage portion forming a storage space  10,  includes an inclined inner wall portion  20  that is connected to a base portion so that the diameter of the inclined inner wall portion gradually decreases; a concave portion  22  is formed at a part of the inclined inner wall portion; and the concave portion  22  includes a concave portion side surface  22   b  that is connected to a concave portion bottom surface  22   a.  The concave portion  22  is formed at a position, where the concave portion crosses an interface S between the specimen centrifuged during rotation and air, in a radial direction with respect to the central axis; and the maximum width of the concave portion  22  in a circumferential direction around the central axis is included in a range of 2 mm to a length of 20% of the whole circumference.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a Continuation of PCT International Application No.PCT/JP2014/058274 filed on Mar. 25, 2014, which claims priority under 35U.S.C §119(a) to Patent Application No. 2013-070995 filed in Japan onMar. 29, 2013 and Patent Application No. 2014-046087 filed in Japan onMar. 10, 2014, all of which are hereby expressly incorporated byreference into the present application.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a centrifugal separation container, acentrifugal separation device that centrifugally separates components ofa specimen present in a container by rotating the container about acentral axis of the container as a rotation axis, and a centrifugalseparation method using the centrifugal separation container and thecentrifugal separation device.

2. Description of the Related Art

A centrifugal separation method of centrifugally separating componentsof a specimen, such as blood, present in a container by rotating thecontainer has been known in the related art. In this centrifugalseparation method, a centrifugal separation container, which includes aninner wall inclined so as to rise toward the outer periphery from thecenter and includes a storage portion forming a storage space storing aspecimen in the container, is used and the container is rotated after aspecimen is injected into the storage space. Further, components havinga low specific gravity in the respective components of the specimen areseparated first by a centrifugal force, which is caused by the rotationof the container, so that the components sequentially form a layerstructure toward an outer peripheral side from an inner peripheral side.After that, when the rotation of the container stops, a low specificgravity component present on the inner peripheral side is generallyreleased from the layer structure body and is stored on the bottom ofthe container.

However, when the centrifugal separation container in the related art isused, a low specific gravity component is not significantly releasedfrom the layer structure body even when the rotation of the containerstops. For this reason, there is a problem in that considerable time isrequired until a low specific gravity component is stored on the bottomof the container. Particularly, when blood is centrifugally separated, asolvent may be applied to the inner wall of the container for theprevention of hemolysis. However, since the solvent causes the lowspecific gravity component (blood plasma) to be not easily released, theabove-mentioned problem is significant. Further, since the amount of aspecimen to be treated in the centrifugal separation container at a timeas described above is in the range of 600 μL to 800 μL, the amount of aspecimen, which can be recovered, is reduced when the centrifugalseparated components stick to the inside of the storage portion. Forthis reason, a problem that the necessary amount of a specimen cannot berecovered may also occur.

Accordingly, various methods have been proposed in order to improve therecovery efficiency of a low specific gravity component. For example,JP2001-239185A discloses a method of facilitating the release of a lowspecific gravity component from the layer structure body by inducing thecapillary phenomenon of a low specific gravity component using acentrifugal separation container that includes capillary phenomenoninducing structures formed on an inner wall surface of a storage portionthereof. Further, U.S. Pat. No. 7,947,186B discloses a method offacilitating the flow of a low specific gravity component andfacilitating the release of a low specific gravity component from thelayer structure body by using a centrifugal separation container thatincludes a hydrophilic region and a hydrophobic region formed on aninner wall surface of a storage portion.

SUMMARY OF THE INVENTION

However, since a capillary phenomenon is used in the method disclosed inJP2001-239185A, there is a limit to the induction rate of the lowspecific gravity component. For this reason, it cannot be said thatrecovery efficiency is sufficient in terms of time required to recovercomponents. Meanwhile, in the method disclosed in U.S. Pat. No.7,947,186B, a hydrophilic region having a predetermined shape is formedusing a gel film on the storage portion. However, it is not easy toseparately form the hydrophilic region and the hydrophobic region inappropriate shapes. Accordingly, processes for manufacturing thecontainer are complicated in this method. For this reason, there isstill a problem in that manufacturing costs of the container areincreased.

The invention has been made in consideration of the above-mentionedproblems, and an object of the invention is to provide a centrifugalseparation container and a centrifugal separation method that can moreefficiently recover centrifugally separated components of a specimen.

In order to solve the above-mentioned problems, according to an aspectof the invention, there is provided a centrifugal separation containerthat is used in a method of centrifugally separating a first specificgravity component and a second specific gravity component, of which aspecific gravity of the second gravity component is higher than aspecific gravity of the first specific gravity component, contained in aspecimen injected into a storage space by rotating a container about acentral axis of the container as a rotation axis. The centrifugalseparation container includes a storage portion that forms the storagespace. The storage portion includes an inclined inner wall portion ofwhich a diameter gradually decreases from an upper end toward a lowerend thereof and the lower end is connected to a base portion; a concaveportion is formed at a part of the inclined inner wall portion; theconcave portion includes a concave portion side surface that isconnected to a concave portion bottom surface with a width of theconcave portion gradually decreases toward the concave portion bottomsurface from the inclined inner wall portion; the concave portion isformed at a position, where the concave portion crosses an interfacebetween the specimen centrifuged during rotation and air, in a radialdirection with respect to the central axis; and the maximum width of theconcave portion in a circumferential direction around the central axisis included in a range of 2 mm to a length of 20% of the wholecircumference passing through the concave portion having a center on thecentral axis.

In the centrifugal separation container according to the aspect of theinvention, it is preferable that a connecting portion between theinclined inner wall portion and the concave portion side surface has acurvature. Further, it is preferable that a connecting portion betweenthe concave portion side surface and the concave portion bottom surfacehas a curvature.

Furthermore, in the centrifugal separation container according to theaspect of the invention, it is preferable that a mean depth of theconcave portion is 0.5 mm or more and it is preferable that the maximumdepth of the concave portion is in the range of 0.5 mm to 2 mm. It ispreferable that the maximum width of the concave portion is 10 mm orless.

Moreover, in the centrifugal separation container according to theaspect of the invention, it is preferable that the concave portion hasthe shape of a fan.

Further, the centrifugal separation container according to the aspect ofthe invention can employ a structure in which one concave portion isformed. In this case, it is preferable that the centrifugal separationcontainer further includes a balancing portion that offsets a deviationof the center of gravity from the central axis caused by the formationof the concave portion to balance the container. It is preferable thatthe balancing portion is provided on the inclined inner wall portion ata position symmetrical to the position of the concave portion withrespect to the central axis.

Alternatively, the centrifugal separation container according to theaspect of the invention can employ a structure in which two to fourconcave portions are formed. In this case, it is preferable that theconcave portions are evenly disposed in the circumferential direction.

Further, in the centrifugal separation container according to the aspectof the invention, it is preferable that the maximum length of theconcave portion is in the range of 5 mm to 15 mm.

Furthermore, in the centrifugal separation container according to theaspect of the invention, it is preferable that the concave portion isformed from the uppermost portion of the inclined inner wall portion.

Moreover, in the centrifugal separation container according to theaspect of the invention, it is preferable that the storage portionincludes a trap portion that is connected to an upper end of theinclined inner wall portion and forms a trap space housing the secondspecific gravity component when the specimen is centrifugally separatedand a layer structure body is formed on an outer peripheral side of thestorage space.

Further, in the centrifugal separation container according to the aspectof the invention, it is preferable that a thixotropic separating agenthaving a specific gravity between the specific gravity of the firstspecific gravity component and the specific gravity of the secondspecific gravity component is provided in the storage space.

A centrifugal separation device according to another aspect of theinvention includes the above-mentioned centrifugal separation container,and a container holder that rotates about a central axis of thecontainer as a rotation axis while holding the container.

In addition, a centrifugal separation method according to still anotheraspect of the invention includes injecting a specimen into theabove-mentioned centrifugal separation container, and centrifugallyseparating a first specific gravity component and a second specificgravity component contained in the specimen by rotating the containerabout a central axis of the container as a rotation axis.

In the centrifugal separation container of the invention, a concaveportion is formed at a part of the inclined inner wall portion, includesa concave portion side surface that is connected to the concave portionbottom surface with a width of the concave portion gradually decreasestoward the concave portion bottom surface from the inclined inner wallportion, has a sufficiently large width, and is formed at a position,where the concave portion crosses an interface between the specimencentrifuged during rotation and air, in a radial direction with respectto the central axis. According to the container of the invention, aportion of the first specific gravity component, which is present abovethe concave portion, is more easily released from the layer structurebody than portions of the first specific gravity component that arepresent in other regions. Accordingly, a portion of the first specificgravity component, which is present above the concave portion, isreleased first from the layer structure body, and portions of the firstspecific gravity component, which are present in other regions, arereleased from the layer structure body so as to be pulled to the portionof the first specific gravity component, which is present above theconcave portion, due to the release of the portion of the first specificgravity component present above the concave portion. The concave portioncan be easily formed simultaneously with the molding of the container.As a result, centrifugally separated components of the specimen can bemore efficiently recovered,

Further, since centrifugal separation is performed using the centrifugalseparation container of the invention in the centrifugal separationdevice and the centrifugal separation method of the invention,centrifugally separated components of the specimen can be moreefficiently recovered.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1A to 1C are schematic views showing the structure of acentrifugal separation container according to an embodiment.

FIG. 2 is a schematic sectional view of a body member of the containertaken along line X-X of FIG. 1.

FIG. 3 is a schematic sectional view showing the internal structure ofthe container taken along line X-X of FIG. 1.

FIG. 4 is a schematic sectional view showing the structure of acentrifugal separation device.

FIG. 5 is a schematic sectional view showing an internal state of thecontainer during centrifugal separation.

FIGS. 6A to 6D are schematic sectional views showing processes of acentrifugal separation method.

FIGS. 7A to 7E are schematic views showing other structures of a concaveportion of the centrifugal separation container.

FIGS. 8A and 8B are schematic views showing other structures of theconcave portion of the centrifugal separation container.

FIGS. 9A and 9B are schematic views showing the structure of acentrifugal separation container according to an example.

FIGS. 10A to 10C are views showing the sectional profile of a portionnear the concave portion based on an inclined surface of an inclinedinner wall portion.

FIG. 11 is a graph showing results of the example.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

An embodiment of the invention will be described below with reference tothe drawings, but the invention is not limited to the embodiment.Meanwhile, for easy visual recognition, the scale and the like of eachof components shown in the drawings are made to be appropriatelydifferent from the actual scale and the like.

FIGS. 1A to 1C are schematic views showing the structure of acentrifugal separation container 1 according to the embodiment,Particularly, FIG. 1A is a perspective view of a body member 2 of thecontainer 1, FIG. 1B is a perspective view of a lid member 3 of thecontainer 1, and FIG. 1C is an enlarged view of a concave portion 22formed at an inclined inner wall portion 20 of the body member 2.Further, FIG. 2 is a schematic sectional view of the body member 2 ofthe container 1 taken along line X-X of FIG. 1, and FIG. 3 is aschematic sectional view showing the internal structure of the container1 taken along line X-X.

The container 1 according to this embodiment includes the body member 2and the lid member 3 of the container as shown in FIGS. 1 to 3. The bodymember 2 includes an inclined inner wall portion 20, a base portion 21,a trap bottom surface portion 23, a trap side surface portion 26, afitting portion 24 that is fitted to the lid member 3, and an outersupport wall portion 25 that supports these portions. The lid member 3includes an opening portion 30 that forms an opening 31 through which aspecimen is injected, and a trap upper surface portion 33 that forms atrap space 10 a together with the trap bottom surface portion 23 and thetrap side surface portion 26 when being fitted to the body member 2.

The container 1 has an internal structure substantially axisymmetricwith respect to an axis (a central axis C of the container), whichpasses through the center of the base portion 21 and is perpendicular tothe base portion 21, (in other words, a structure like a sort ofrotating body having a center on the central axis C), and has asubstantially columnar appearance as a whole. When centrifugalseparation is performed, the lid member 3 is, for example, fixed to thefitting portion 24 while being fitted to the fitting portion 24 of thebody member 2 and the container 1 is rotated about the central axis C asa rotation axis.

When the body member 2 and the lid member 3 are fitted to each other, astorage space 10 into which a specimen is injected is formed as shown inFIG. 3. Specifically, the storage space 10 is a space that is surroundedby the inclined inner wall portion 20, the base portion 21, the trapbottom surface portion 23, the trap side surface portion 26, the trapupper surface portion 33, and the opening portion 30. Particularly, aspace 10 a, which is formed by the trap bottom surface portion 23, thetrap side surface portion 26, and the trap upper surface portion 33, ofthe storage space serves as a trap space that traps a component of thespecimen having high specific gravity when the container is rotated tocentrifuge the specimen. That is, the inclined inner wall portion 20,the base portion 21, the trap bottom surface portion 23, the trap sidesurface portion 26, the trap upper surface portion 33, and the openingportion 30 correspond to a storage portion of the invention; and thetrap bottom surface portion 23, the trap side surface portion 26, andthe trap upper surface portion 33 correspond to a trap portion of theinvention.

The inclined inner wall portion 20 includes an inclined surface which isformed in a substantially conical shape and of which a diameter isreduced toward a lower end of the inclined surface connected to the baseportion 21 from an upper end thereof connected to the trap bottomsurface portion 23. A lower portion of the storage space 10 is formed bythe inclined surface. Further, a part of the inclined inner wall portion20 forms the concave portion 22. The concave portion 22 includes aconcave portion side surface 22 b that allows the width of the concaveportion 22 to gradually decreases toward a concave portion bottomsurface 22 a from the inclined inner wall portion 20 and is connected tothe concave portion bottom surface 22 a. It is preferable that aconnecting portion between the inclined inner wall portion 20 and theconcave portion side surface 22 b has a curvature to prevent thehemolysis of the specimen and a connecting portion between the concaveportion bottom surface 22 a and the concave portion side surface 22 bhas a curvature. Further details of the concave portion 22 will bedescribed below. Further, the inclined inner wall portion 20 includes aprotrusion 27 at a position symmetrical to the concave portion 22 withrespect to the central axis C.

The protrusion 27 is to adjust the position of the center of gravity ofthe container 1 that is changed due to the formation of the concaveportion 22 of the inclined inner wall portion 20, and corresponds to abalancing portion of the invention. Only one concave portion 22 has beenformed at an inclined inner wall portion 20 in this embodiment. However,since only one concave portion 22 is formed, the position of the centerof gravity of the container 1 according to this embodiment may deviatefrom the central axis of the container in design. Since the rotation ofthe container 1 becomes unstable in this case, it is not preferable thatonly one concave portion 22 is formed. Accordingly, since the protrusion27 is provided in this embodiment to offset a difference in the momentof inertia that is caused since a part (concave portion) of the inclinedinner wall portion 20 becomes distant from the central axis C, the massof a portion symmetrical to the position of the concave portion 22 withrespect to the central axis C is increased. Further, the balancingportion only has to balance the container and is not limited to theprotrusion-shaped structure. For example, a structure in which ahigh-density material is embedded in the inclined inner wall portion 20at a position symmetrical to the position of the concave portion 22 withrespect to the central axis C may be employed as the balancing portion.Furthermore, the balancing portion may not be provided on the inclinedinner wall portion 20 and may be provided on the outer support wallportion 25. Meanwhile, the balancing portion is not essential in theinvention, and does not need to be provided, for example, when theabove-mentioned deviation of the center of gravity does not occuroriginally or when the deviation of the center of gravity is negligiblysmall in regard to centrifugal separation. Examples of a case in whichthe deviation of the center of gravity does not occur may include a casein which a plurality of concave portions are disposed so as to bebalanced, and a case in which the thickness of a portion of the inclinedinner wall portion 20 corresponding to a concave portion is adjusted tobe small even if one concave portion is formed.

The base portion 21 connected to the lower end of the inclined innerwall portion 20 includes a substantially horizontal flat surface that isconnected to the lower end of the inclined surface of the inclined innerwall portion 20 so as to have a curvature. The flat surface forms thebottom surface of the storage space 10 in this embodiment, but the baseportion 21 of the invention does not need to be flat and may be a risingcurved surface. Since the container 1 is rotated about the central axisC, a specimen present near the central axis C tends to be hardlycentrifugally separated. However, when the base portion 21 is formed ofa rising curved surface, the centrifugal separation performance of thecontainer can be further improved. The reason for this is as follows:when the base portion 21 is formed of a rising curved surface, a forcein a direction away from the central axis C (which is a gravitycomponent along the curved surface) is applied to a specimen presentnear the base portion 21 at the time of the injection of a specimen. Asa result, since the specimen present near the base portion 21 is likelyto be separated from the central axis C without staying near the centralaxis C during the rotation of the container 1, a centrifugal force ismore efficiently applied to the specimen.

The trap bottom surface portion 23 connected to the upper end of theinclined inner wall portion 20 includes a substantially horizontal flatsurface that is connected to the upper end of the inclined surface ofthe inclined inner wall portion 20 so as to have a curvature. The flatsurface forms the bottom surface of the trap space 10 a. The trap sidesurface portion 26 includes a perpendicular surface that is connected tothe flat surface of the trap bottom surface portion 23 so as to beperpendicular to the flat surface of the trap bottom surface portion 23,The perpendicular surface forms the side surface of the trap space 10 a.

The trap space 10 a has an annular shape having a center on the centralaxis C, and the volume of the trap space 10 a is designed according tothe amount of a specimen to be injected. Further, a separating agent (orseparation gel) is disposed, for example, in the trap space 10 a inadvance. The separating agent is appropriately selected from materials,which have an intermediate specific gravity between the specificgravities of the components, according to a low specific gravitycomponent (first specific gravity component) and a high specific gravitycomponent (second specific gravity component) that are contained in thespecimen and are to be separated. Specifically, when blood plasma (lowspecific gravity component) and blood cells (high specific gravitycomponent) contained in blood are to be separated, a material having anintermediate specific gravity between the specific gravity of the bloodplasma and the specific gravity of the blood cell may be selected as theseparating agent.

The outer support wall portion 25 extends downward from the trap sidesurface portion 26 while surrounding the entire inclined inner wallportion 20, and a lower end of the outer support wall portion 25 extendsdownward further than the base portion 21. Accordingly, the body member2 is stably supported.

The opening portion 30 of the lid member 3 has, for example, a truncatedconical shape and includes an inclined surface of which a diameter isreduced toward the opening 31. An upper portion of the storage space 10is formed by the inclined surface. In this embodiment, the container 1is rotated while the opening 31 is open. However, the opening may beadapted to be capable of being opened and closed as necessary. The trapupper surface portion 33 connected to the lower end of the openingportion 30 includes a substantially horizontal flat surface that isconnected to the lower end of the inclined surface of the openingportion 30 so as to have a curvature, The flat surface forms the uppersurface of the trap space 10 a.

Further, centrifugal separation is performed by, for example, acentrifugal separation device 50 shown in FIG. 4. The centrifugalseparation device 50 includes an opening/closing lid 51 a, a housing 51that forms a housing space 52 housing the container 1, and a rotatingtable 53 (container holder) which is provided in the housing space 52and on which the container 1 is mounted. The container 1 is brought intothe housing space 52 while the opening/closing lid 51 a is open, and ismounted on the rotating table 53. The rotating table 53 is supported tobe rotatable by a rotating mechanism (not shown) (for example, a motoror the like), and rotates the container 1 so that the central axis C ofthe container 1 mounted on the rotating table 53 corresponds to arotation axis R.

The concave portion 22 of the inclined inner wall portion 20 will bedescribed. FIG. 5 is a schematic sectional view showing an internalstate of the container during centrifugal separation. FIG. 5 shows astate in which a layer structure body as a product of centrifugalseparation is formed in an outer peripheral region of the storage space10 as a result of the centrifugal separation of a specimen including alow specific gravity component (first specific gravity component) 5 aand a high specific gravity component (second specific gravitycomponent) 5 b. The layer structure body has a structure in which thelow specific gravity component 5 a, the separating agent 4, and the highspecific gravity component 5 b are stacked from the inner peripheralside in this order. As shown in FIG. 5, the concave portion 22 is formedat a position, where the concave portion 22 crosses an interface Sbetween the specimen centrifuged during rotation (particularly, the lowspecific gravity component 5 a after centrifugal separation) and air, inthe radial direction with respect to the central axis C. Accordingly, aportion of the low specific gravity component 5 a present on the concaveportion 22 is more easily released from the layer structure body thanportions of the low specific gravity component 5 a present in otherregions. Since it is possible to easily form the concave portion 22simply by adjusting the shape of a mold when the body member 2 ismanufactured by injection molding or the like, an increase of themanufacturing cost of the container is not caused. Further, the concaveportion 22 includes the concave portion side surface 22 b in thisembodiment, but the concave portion side surface 22 b may be formedintegrally with the concave portion bottom surface 22 a. Furthermore,each of the concave portion side surface 22 b and the concave portionside surface 22 a may be formed of a curved surface.

It is preferable that the shape of the concave portion 22 is a fan shapehaving a center on the central axis C (including a truncated fan shapeof which a portion including a central portion is cut out) so that anobstacle occurring when the specimen is centrifuged or when the lowspecific gravity component moves downward along the inclined surface ofthe inclined inner wall portion 20 is reduced. A fan shape (circularsector) of the invention means a shape of which at least a part includesa side parallel to a radial direction in a top view, and each corner ofthe fan shape may be rounded. Further, it is preferable that a side,which mainly extends in the circumferential direction around the centralaxis C, has an arc shape in the circumferential direction. Meanwhile,the concave portion 22 includes the flat bottom surface 22 a along theinclined surface of the inclined inner wall portion 20 in thisembodiment, but the bottom of the concave portion 22 is not limited to aflat surface.

The maximum width W1 (FIG. 1C) of the concave portion 22 in thecircumferential direction around the central axis C is set to besufficiently larger than a width, which causes a capillary phenomenonbetween the specimen and the concave portion, to facilitate the releaseof the low specific gravity component 5 a from the layer structure body.For example, it is preferable that the maximum width W1 of the concaveportion 22 is 2 mm or more and it is more preferable that the maximumwidth W1 of the concave portion 22 is 3 mm or more. Further, if areleasing force is locally generated when the low specific gravitycomponent is released from the layer structure body, the release isfacilitated. Furthermore, in order to easily balance the container, itis preferable that the maximum width W1 is equal to or smaller than 20%of the length of the entire circumference of the inclined inner wallportion in the circumferential direction around the central axis C at aposition corresponding to the maximum width of the concave portion, thatis, a length corresponding to 20% of an angular range of the concaveportion. Moreover, considering the size of a general centrifugalseparation container, it is preferable that the maximum width W1 is 10mm or less and it is particularly preferable that the maximum width W1is 8 mm or less.

Further, the maximum length W2 (FIG. 1C) of the concave portion 22 inthe radial direction with respect to the central axis C in a top view isnot particularly limited as long as the concave portion 22 crosses theinterface S. Meanwhile, the maximum length W2 means a length along theinclined surface of the inclined inner wall portion 20. Generally, themaximum value and the minimum value of the amount of a specimenavailable to be used are determined as specifications of eachcentrifugal separation container. Accordingly, if a condition in whichthe concave portion 22 crosses the interface S is satisfied in regard tothe amount of a specimen within the range of the specifications, it isgenerally sufficient. Therefore, an upper end of the concave portion 22may be set to be on the side (outer peripheral side) above the positionof the interface when the amount of a specimen is the lower limit of therange of the specifications, and a lower end of the concave portion 22may be set to be on the side (inner peripheral side) below the positionof the interface when the amount of a specimen is the upper limit of therange of the specifications. However, to prevent the hemolysis of thespecimen caused by the concave portion 22 and to easily balance thecontainer when the specimen is centrifuged, it is preferable that themaximum length W2 is in the range of 5 mm to 15 mm and is in the rangeof 6 mm to 12 mm and it is more preferable that the maximum length W2 isin the range of 7 mm to 10 mm. Furthermore, the depth of the concaveportion 22 is also not particularly limited, However, to generate asufficient releasing force during the release of the low specificgravity component from the layer structure body and to prevent thespecimen from remaining in the concave portion, it is preferable thatthe mean depth of the concave portion is 0.5 mm or more and it ispreferable that the maximum depth of the concave portion is in the rangeof 0.5 mm to 2 mm. In addition, in terms of the prevention of hemolysis,it is preferable that the inclination of an inner portion of the concaveportion 22 is 0.5 mm/mm (that is, tan α=0.5 and α is about(26.6°) orless from the inclined surface of the inclined inner wall portion 20.Here, the “depth” means a difference between the height of a point,which is positioned in the concave portion 22, and the height of avirtual inclined surface that extends from the inclined inner wallportion 20 so that it is assumed that the concave portion 22 is notformed. Further, the “mean depth” means a value calculated from V/A whenthe volume of the concave portion 22 (the volume of a space formed bythe virtual inclined surface and the concave portion 22) is denoted by Vand the projected area of the concave portion 22 on the inclined surfaceof the inclined inner wall portion 20 (that is, the area of the virtualinclined surface) is denoted by A. Furthermore, the “maximum depth”means the maximum difference between the height of a point, which ispositioned in the concave portion 22, and the height of the virtualinclined surface.

Processes of a centrifugal separation method using the centrifugalseparation container 1 and the centrifugal separation device 50, whichhave been described above, will be described below. FIGS. 6A to 6D areschematic sectional views showing the processes of the centrifugalseparation method.

First, the container 1 in which the separating agent 4 is disposed inthe trap space 10 a in advance is prepared, and a specimen 5 is injectedinto the storage space 10 from the opening 31 of the container 1 (FIG.6A). The injection of the specimen 5 is performed using, for example, apipette or an injector. Next, the container 1 into which the specimen 5is injected is mounted on the rotating table 53 of the centrifugalseparation device 50 and is rotated. At this time, the contents of thecontainer 1 are separated according to specific gravity by a centrifugalforce of rotation, and the layer structure body is formed on the outerperipheral side of the storage space 10 (FIG. 6B). The high specificgravity component 5 b is trapped in the trap space 10 a by trap portions(the trap bottom surface portion 23, the trap side surface portion 26,and the trap upper surface portion 33) and the separating agent 4. Then,when the rotation of the container 1 stops, a portion of the lowspecific gravity component 5 a, which is present above the concaveportion 22, starts to be released first due to the presence of theconcave portion 22 (FIG. 6C) and other portions are gradually releasedso as to follow the release of the portion that is present above theconcave portion 22. Meanwhile, the high specific gravity component 5 bremains in the trap space as it is. Further, when the entire lowspecific gravity component 5 a is released from the layer structurebody, the low specific gravity component Sa pools on the lower side inthe storage space 10. Accordingly, only the low specific gravitycomponent Sa can be extracted and recovered (FIG. 6D).

As described above, according to the container of this embodiment, aportion of the low specific gravity component, which is present abovethe concave portion, is more easily released from the layer structurebody than portions of the low specific gravity component that arepresent in other regions. Accordingly, a portion of the low specificgravity component, which is present above the concave portion, isreleased first from the layer structure body, and portions of the lowspecific gravity component, which are present in other regions, arereleased from the layer structure body so as to be pulled to the portionof the low specific gravity component, which is present above theconcave portion, due to the release of the portion of the low specificgravity component present above the concave portion. As a result,centrifugally separated components of the specimen can be moreefficiently recovered. Further, the concave portion can be easily formedwithout other members simultaneously with the molding of the container.For this reason, it is possible to reduce manufacturing cost bysimplifying processes for manufacturing the container.

Furthermore, since centrifugal separation is performed using thecentrifugal separation container of the invention in the centrifugalseparation device and the centrifugal separation method of theinvention, centrifugally separated components of the specimen can bemore efficiently recovered.

Other Embodiments

The body member or the concave portion of the container 1 of theinvention is not limited to the structure of the body member or theconcave portion of the above-mentioned embodiment.

For example, FIG. 7A is a schematic top view showing the structure of abody member 2 a including a concave portion 35 of which the shape isdifferent from the shape of the concave portion of the above-mentionedembodiment. The body member 2 a of FIG. 7A includes the concave portion35 that is formed over the base portion 21 from the upper end of theinclined inner wall portion 20. Further, FIG. 7B is a schematic top viewshowing the structure of a body member 2 b including a concave portion36 of which the shape is different from the shape of the concave portionof the above-mentioned embodiment. The body member 2 b of FIG. 7Bincludes a concave portion 36 that is formed so as to be separated fromthe upper end of the inclined inner wall portion 20 and the base portion21.

FIG. 7C is a schematic top view showing the structure of a body member 2c of which the shape of a concave portion is the same as that of theembodiment but the disposition of a balancing portion is different fromthat of the embodiment. The concave portion 22 of FIG. 7C is formed fromthe upper end of the inclined inner wall portion 20 as in theembodiment. The balancing portion of FIG. 7C is provided with twoprotrusions 27 each of which is the same as that of the embodiment.Further, the two protrusions 27 are disposed so as to be symmetric toeach other with respect to a radial line that passes through theposition of the protrusion 27 of the above-mentioned embodiment (thatis, the position symmetrical to the position of the concave portion 22with respect to the central axis C), and balance the container as awhole.

Furthermore, FIGS. 7D and 7E are schematic top views showing thestructures of body members 2 d and 2 e including concave portions eachof which has the same shape as the concave portion of theabove-mentioned embodiment but of which the number is different fromthat of the concave portion of the above-mentioned embodiment.Specifically, the body member 2 d of FIG. 7D includes two concaveportions 22 each of which is the same as the concave portion of theabove-mentioned embodiment, and the two concave portions 22 are evenlydisposed at an interval of 180°. Meanwhile, the body member 2 e of FIG.7E includes three concave portions 22 each of which is the same as theconcave portion of the above-mentioned embodiment, and the three concaveportiones 22 are evenly disposed at an interval of 120°. When aplurality of concave portiones are evenly disposed as described above,the container can be balanced as a whole. For this reason, a balancingportion is not necessary. For example, the number of the concaveportions is appropriately selected according to the capacity of thecontainer (the volume of the storage space) or the range of thespecifications of the amount of a specimen.

Further, the fan-shaped concave portion having a center on the centralaxis C has been described in the above-mentioned embodiment and FIGS. 7Ato 7E, but the invention is not limited thereto. For example, FIG. 8A isa schematic top view showing the structure of a body member 2 fincluding a fan-shaped concave portion 37 that does not have a center onthe central axis C. Furthermore, FIG. 8B is a schematic top view showingthe structure of a body member 2 g including a substantially rectangularconcave portion 38. Effects of the invention are sufficiently obtainedeven in the cases of the concave portiones having these shapes. However,when the shape of the concave portion is not the shape of a fan asdescribed above, there is a concern that a connecting portion betweenthe concave portion and the other inclined inner wall portion may causean obstacle when the specimen is centrifuged or when the low specificgravity component moves downward along the inclined surface of theinclined inner wall portion 20. For this reason, it is preferable thatthe shape of the concave portion is the shape of a fan.

EXAMPLES

Examples of the centrifugal separation method using the centrifugalseparation container of the invention will be described below.

Example 1

A centrifugal separation container shown in FIGS. 9A and 9B was used inthis example. FIG. 9A is a sectional view of the container used in theexample, and FIG. 9B is a perspective view of the container. Specificdimensions of the main structure of the container are as follows:

Diameter φ1 of a trap space=22.5 mm

Diameter φ2 of the circumference including a balancing protrusion=14 mm

Diameter φ3 of the entire container=26 mm

Height L1 of a body member=18.1 mm

Depth L2 of a space formed by an inclined inner wall portion=9 mm

Height L3 of the trap space=4.8 mm

Depth D of a concave portion=0.8 mm

Angle θ1 between an inclined surface of the inclined inner wall portionand a central axis=48°

A circumferential angular range θ2 occupied by the concave portion=47°

A distance R between a base portion and the concave portion along theinclined surface of the inclined inner wall portion=4.1 mm

Further, FIGS. 10A to 10C are views showing the sectional profile of aportion near the concave portion based on an inclined surface of aninclined inner wall portion. FIG. 10A shows two directions (a radialdirection Dr and an axial direction Da) along which the section of theconcave portion is taken, and FIGS. 10B and 10C show the sectionalprofile of the concave portion taken along the radial direction Dr andthe sectional profile of the concave portion taken along the axialdirection Da, respectively. In the centrifugal separation container ofthe example, the concave portion includes a bottom surface and the widthL4 of the base portion is 3 mm at a position where the section is taken.Furthermore, the width L5 of an inclined surface, which connects thebottom surface to a reference surface, (that is, an inclined surface ofthe inclined inner wall portion) is 1.6 mm and an inclination θ3 of theinclined surface is about 26.6° (tan θ3=0.5). Moreover, the length L6 ofthe bottom surface of the concave portion in the axial direction Da is 3mm. Further, the length L7 of an inner peripheral inclined surface,which connects the bottom surface to the reference surface, is 1.6 mmand an inclination θ4 of the inclined surface is about 26.6°. Meanwhile,the outer peripheral side of the bottom surface is inclined so as torise by a height of 0.6 mm per 2 mm (L8) (that is, since tan θ5 is 0.3,θ5 is about 16.7°). The concave portion is connected to the trap bottomsurface portion while the depth of the concave portion is maintainedafter the inclination of the concave portion.

600 μL of SCOLLECT (manufactured by Sekisui Medical Co., Ltd.) wasdispensed to the centrifugal separation container as a serum separatingagent, and 500 μL of whole blood was dispensed. After that, a specimenwas centrifuged for 90 seconds (for 110 seconds when 10 seconds at thetime of acceleration and 10 seconds at the time of deceleration areincluded) at a rotational speed of 24000 rpm. Further, the centrifugalseparation method was performed twice.

Example 2 and Comparative Example

Centrifugal separation was performed using a container, which includedtwo concave portions, as in Example 2. The concave portions wereprovided at positions that face each other with a central axisinterposed therebetween, Other conditions were the same as those ofExample 1. Furthermore, centrifugal separation was performed using acontainer, which did not include a concave portion and of which aninclined surface of an inclined inner wall portion was flat, asComparative example. Other conditions were the same as those of Example1.

Results

FIG. 11 is a chart showing the results for the example and thecomparative example. It can be understood from this table that moreblood plasma can be recovered than for a container not including aconcave portion in case where the centrifugal separation container ofthe invention is used.

Explanation of References

1: centrifugal separation container

2: body member

3: lid member

4: separating agent

5: specimen

5 a: low specific gravity component (first specific gravity component)

5 b: high specific gravity component (second specific gravity component)

10: storage space

10 a: trap space

20: inner wall portion

21: base portion

22: concave portion

22 a: concave portion bottom surface

22 b: concave portion side surface

23: trap bottom surface portion

24: fitting portion

25: outer support wall portion

26: trap side surface portion

27: protrusion

30: opening portion

31: opening

33: surface portion

50: centrifugal separation device

R: rotation axis

S: interface

W1: maximum width

W2: maximum length

What is claimed is:
 1. A centrifugal separation container that is usedin a method of centrifugally separating a first specific gravitycomponent and a second specific gravity component, of which a specificgravity of the second gravity component is higher than a specificgravity of the first specific gravity component, contained in a specimeninjected into a storage space by rotating a container about a centralaxis of the container as a rotation axis, the centrifugal separationcontainer comprising: a storage portion that forms the storage space,wherein the storage portion includes an inclined inner wall portion ofwhich a diameter gradually decreases from an upper end toward a lowerend thereof and the lower end is connected to a base portion, a concaveportion is formed at a part of the inclined inner wall portion, theconcave portion includes a concave portion side surface that isconnected to a concave portion bottom surface with a width of theconcave portion gradually decreases toward the concave portion bottomsurface from the inclined inner wall portion, the concave portion isformed at a position, where the concave portion crosses an interfacebetween the specimen centrifuged during rotation and air, in a radialdirection with respect to the central axis, and the maximum width of theconcave portion in a circumferential direction around the central axisis included in a range of 2 mm to a length of 20% of the wholecircumference passing through the concave portion having a center on thecentral axis.
 2. The centrifugal separation container according to claim1, wherein a connecting portion between the inclined inner wall portionand the concave portion side surface has a curvature.
 3. The centrifugalseparation container according to claim 1, wherein a connecting portionbetween the concave portion side surface and the concave portion bottomsurface has a curvature.
 4. The centrifugal separation containeraccording to claim 2, wherein a connecting portion between the concaveportion side surface and the concave portion bottom surface has acurvature.
 5. The centrifugal separation container according to claim 1,wherein a mean depth of the concave portion is 0.5 mm or more.
 6. Thecentrifugal separation container according to claim 2, wherein a meandepth of the concave portion is 0.5 mm or more.
 7. The centrifugalseparation container according to claim 1, wherein the maximum depth ofthe concave portion is in the range of 0.5 mm to 2 mm.
 8. Thecentrifugal separation container according to claim 1, wherein themaximum width of the concave portion is 10 mm or less.
 9. Thecentrifugal separation container according to claim 1, wherein theconcave portion has the shape of a fan.
 10. The centrifugal separationcontainer according to claim 1, wherein one concave portion is formed.11. The centrifugal separation container according to claim 10, furthercomprising: a balancing portion that offsets a deviation of the centerof gravity from the central axis caused by the formation of the concaveportion to balance the container.
 12. The centrifugal separationcontainer according to claim 11, wherein the balancing portion isprovided on the inclined inner wall portion at a position that issymmetrical to the position of the concave portion with respect to thecentral axis.
 13. The centrifugal separation container according toclaim 1, wherein two to four concave portions are formed.
 14. Thecentrifugal separation container according to claim 13, wherein theconcave portions are evenly disposed in the circumferential direction.15. The centrifugal separation container according to claim 1, whereinthe maximum length of the concave portion is in the range of 5 mm to 15mm.
 16. The centrifugal separation container according to claim 1,wherein the concave portion is formed from the uppermost portion of theinclined inner wall portion.
 17. The centrifugal separation containeraccording to claim 1, wherein the storage portion includes a trapportion that is connected to an upper end of the inclined inner wallportion and forms a trap space housing the second specific gravitycomponent when the specimen is centrifugally separated and a layerstructure body is formed on an outer peripheral side of the storagespace.
 18. The centrifugal separation container according to claim 1,wherein a thixotropic separating agent, which has a specific gravitybetween the specific gravity of the first specific gravity component andthe specific gravity of the second specific gravity component, isprovided in the storage space.
 19. A centrifugal separation devicecomprising: the centrifugal separation container according to claim 1;and a container holder that rotates about a central axis of thecontainer as a rotation axis while holding the container.
 20. Acentrifugal separation method comprising: injecting a specimen into thecentrifugal separation container according to claim 1; and centrifugallyseparating a first specific gravity component and a second specificgravity component, of which a specific gravity of the second gravitycomponent is higher than a specific gravity of the first specificgravity component, contained in the specimen by rotating the containerabout a central axis of the container as a rotation axis.